adccommunitymod (AutomationDirect) asked a question.
Created Date: February 11,2014
Created By: cme
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Hello all... I'm not a motor expert, but I have been recently investigating PM synchronous motors (for servo applications) and I was wondering if you guys could help me with a question that I have: From what I can tell (please correct me if I'm wrong) the basic construction (stator and rotor) of both AC and DC brushless/synchronous motors are the same, the difference comes in the type of feedback sensor. Assuming this, and assuming you could choose whatever feedback sensor you wanted, couldn't you control the same motor with either an AC drive or DC drive? What are the pros/cons of each?
Created Date: February 13,2014
Created by: Adisharr
Most of the applications I get involved with these days either use an AC induction motor with VFD, servo or stepper. They all have their uses. It really comes down to what you need.
Basic categories
Course position control or none? VFD $-$$
Low speed / high torque precision position control? Stepper $$
High speed precision speed or position control? Servo $$$
Need feedback? Open loop stepper with encoder / closed loop stepper / servo / VFD with encoder
Some closed loop stepping systems can achieve servo speeds and do a great job. Also, some (most) servos can run in a pulse mode.
Essentially there are a ton of choices these days. While it can be confusing to narrow it down, it's nice to have options.
Created Date: February 14,2014
Created by: cme
Thanks for the reply, but I'm still wondering about the control of a synchronous motor. Assuming you could choose whatever feedback sensor type you wanted, couldn't you control the same motor with either a DC or and AC drive?
Created Date: February 11,2014
Created by: cme
Hello all... I'm not a motor expert, but I have been recently investigating PM synchronous motors (for servo applications) and I was wondering if you guys could help me with a question that I have:
From what I can tell (please correct me if I'm wrong) the basic construction (stator and rotor) of both AC and DC brushless/synchronous motors are the same, the difference comes in the type of feedback sensor. Assuming this, and assuming you could choose whatever feedback sensor you wanted, couldn't you control the same motor with either an AC drive or DC drive? What are the pros/cons of each?